The present invention relates to improvements in mechanical drive means such as drive means for article transfer or similar machinery. More particularly, the invention relates to an improved drive system including a drive rod in the drive train for a driven member which combines an adjustment means for the rod length with an independent spring loaded adjustment means for shortening the rod and thus limiting the rod drive force responsive to an interruption in the movement of the driven member.
The improved drive rod, for example, will be described in a typical use in the drive system of an egg transfer machine where an adjustment of the path of the egg transfer head and protection against excess transfer head pressures are desirable characteristics for the egg transfer system drive. One such system is shown in my co-pending United States patent application Ser. No. 445,577 entitled IMPROVED METHOD AND MEANS FOR TRANSFERRING EGGS, filed on Feb. 25, 1974. Such a transfer head picks up a number of eggs at a pick-up point and carries them along a predetermined path to an egg placing position at an egg conveyor. The egg transfer head is mounted on a pair of pivotally supported arms with the arms being rocked by a drive shaft coupled through a drive system to a drive motor. The improved drive rod of this invention is incorporated in the drive system so that adjustments of the rod length permit changes in the end positions of the path of the egg transfer head. At the same time, an independent adjustment of the resilient rod coupling permits the rod to shorten when the transfer head encounters an obstruction while moving in one direction, such as the pick-up direction. This capability permits the pick-up head to encounter the operator's hands or another foreign object and to terminate the pick-up head motion without damage to the object or to the machine. It also permits the pick-up head to engage gently and to pick-up eggs of differing sizes or at differing positions as, for example, where the eggs are being removed from the top tray of a stack of trays of increasing height.
Accordingly, an object of the present invention is to provide an improved mechanical drive system for transfer machines or other devices.
Another object of the present invention is to provide an improved drive rod of adjustable length and having an independently adjustable drive force limiting means.
Another object of the present invention is to provide an improved drive system for an egg transfer device.
Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.